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Register suppliers

Supplier registration guide ›

Issue invoices

Issuing guide ›
Invopop is an officially certified invoice provider in Portugal. Our AT Portugal app supports invoice, receipt and delivery note compliance with Portugal’s AT e-invoicing regulation. Automate supplier onboarding, SAF-T report generation, invoice generation with ATCUD, and more. This app enables businesses (and their suppliers) to issue invoices and other document types in accordance with Portuguese law.

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Key features

  • Workflow automation: This app provides automated workflows for issuing invoices, onboarding suppliers, and managing fiscal submissions to the Autoridade Tributária e Aduaneira (AT).
  • Legally compliant PDF documents: Invoices, payments and delivery notes are generated with a certified ATCUD and QR codes, as required by the Portuguese tax legislation.
  • SAF-T (PT): The app makes workflow steps available to manage SAF-T (PT) entries for each supplier.
  • Realtime and manual reporting options: Report in real-time via webservice or generate a file to upload through the AT’s portal.
  • Supplier portal: Suppliers can generate SAF-T PT reports and create authorized series via the Supplier Portal.
  • Supplier registration: Registration completes in a single workflow step, with no manual onboarding for the supplier.
  • White-label support: Invoicing can be performed either under a client’s brand (white-label) or directly by the issuing organization, according to operational needs.

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Supported document types

The current integration supports the following document types for reporting to the AT:Other SAF-T document types beyond those listed above are not currently supported. If you require support for additional document types, please contact us so we can analyze and consider prioritizing their development.Make sure to check out our Supplier registration guide for onboarding suppliers and the Issuing invoices guide for issuing documents.

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FAQ

Invoicing questions
In Portugal, fiscally relevant documents issued through invoicing software must be reported to the Tax Authority (AT). There are two possible reporting models:
  1. SAF-T monthly export – a single XML file including all documents for the month. This file is generated by the invoicing software and then uploaded manually to the AT portal, as there is no API available for submitting it automatically.
  2. Real-time transmission – instead of a monthly file, each invoice is sent individually to the AT at the time of issuance, using the authority’s API.
Whether one model or the other is used usually depends on the issuer’s accountant’s preference (who typically uploads the SAF-T monthly report should they choose that model). Invopop’s AT Portugal app supports both reporting methods, so each supplier can pick the one that best fits their needs.If a supplier uses real-time transmission — the Send document to AT step in the workflow — the documents submitted this way are already communicated to the AT, so they don’t need to upload a monthly SAF-T file for them. The only documents that still require the monthly SAF-T upload are those not reported in real time, such as RG payment receipts, which the AT’s webservice does not accept.
Install the AT Portugal app, register the supplier with their NIF, and pick a reporting model (monthly SAF-T or real-time submission). Run invoices through the AT Issue Invoice workflow — Invopop generates the ATCUD, QR, and signature automatically.
When issuing in Portugal you may see an error similar to:
recording envelope: totals: (payable: too high according to Artigo 40.º do CIVA.)
What it means: Article 40 of the Portuguese VAT Code (Código do IVA) caps the amount a simplified invoice (fatura simplificada) can carry. The limits are:
  • €1,000 for goods sold by retailers or itinerant sellers to buyers who are not taxable persons (final consumers).
  • €100 for every other supply of goods or services.
  • No limit for suppliers under the Article 53 small-business exemption regime (since Decree-Law 35/2025).
Above the applicable limit, a simplified invoice is no longer allowed and the document must be a full invoice (fatura). Note that a simplified invoice can only carry the fields listed in Article 40, so adding the buyer’s name or address to it is not an option — the document type has to change.What to do:
  • Issue the document as a full invoice instead of a simplified one.
  • If the buyer is a taxable person (a business or a freelancer invoicing with a NIF), include their name, address, and NIF — Article 36 requires these identification elements only for taxable-person buyers.
  • If the buyer is a final consumer, no customer identification is required on a full invoice, whatever the amount. If you don’t have their details, leave the customer block out, and Invopop will report the document to the AT under the generic final consumer.
In GOBL, drop the simplified tag from $tags and adjust the customer block as above, then re-run the workflow.
What it means: when a credit note references an invoice issued through Invopop, every credit note line must be matched against the quantity and price still available to credit on the original invoice’s lines. Line #N could not be matched to any of them.For a credit note line to be applied to an invoice line:
  1. Its item.name must be exactly identical to the invoice line’s, and both lines must have the same VAT treatment — the same rate and, where applicable, the same exemption.
  2. Among the lines matching by name and VAT, it must satisfy one of:
    • Same unit price as the invoice line, with a quantity up to the remaining quantity — to credit fewer units at the original price.
    • Same quantity as the invoice line, with a unit price up to the remaining price — to credit part of the amount for the full quantity.
Include only the lines you are crediting — the credit note does not need to mirror the full invoice — and the order of the lines is irrelevant. Availability is cumulative: every accepted credit note reduces the remaining quantity or price, so the total credited per line can never exceed the original invoice amount.What to do: check that line #N’s item name and VAT rate or exemption exactly match a line on the referenced invoice (watch for typos or renamed items), and that it keeps either the original unit price or the original quantity as described above. If everything matches, review credit notes previously issued against the same invoice — the remaining quantity or amount may already have been credited.Note that a credit note supports exactly one preceding reference, and line matching only applies when the referenced invoice was issued through Invopop — references to external series (for example, invoices issued by a previous provider) are accepted without matching.
This error means your workflow includes the Send to the AT step for a payment receipt. Payment receipts are not supported for real-time reporting — the AT does not accept them via the real-time webservice.The fix: remove the Send to the AT step from your payment workflow. RG receipts are only reportable through the monthly SAF-T file. The Record for SAF-T reporting step alone is all you need for full compliance.
Portugal defines two payment receipt types:
  • RG — Outros Recibos: Standard payment receipts, reported through the monthly SAF-T file only. Real-time reporting is not available for this type.
  • RC — Recibo no âmbito do regime de IVA de Caixa: Receipts specific to the VAT Cash accounting regime. RC payments are not currently supported by the AT Portugal app.
See the Portugal tax regime in GOBL for tax categories, NIF rules, and AT-specific extensions. The pt-saft-v1 addon documents fields required by the SAF-T schema.
Registering supplier questions
Run the AT Register Supplier workflow on the supplier, provide their AT web-service credentials, then register at least one series per document type they’ll issue. Both can be done in the supplier portal or through the API (credentials, series). Each series gets a validation code from the AT, used to build the ATCUD on every document. See Register a supplier.
An AT web-services sub-user (username and password) created in the AT portal, in both models. It always needs the WSE permission, to register series; add WFA if documents are reported in real time.
Invopop stores the AT web-service credentials encrypted at rest, in both models: they’re needed to register series, and for real-time reporting. In the SAF-T model, the supplier (or their accountant) also downloads the monthly SAF-T file and uploads it to the AT’s portal.
Reporting questions
Real-time model: per invoice. SAF-T model: once per month, by the 5th of the following month. The choice is made in your workflow: include the Send document to AT step for real-time reporting, or leave it out and report through the monthly SAF-T file.
For invoice-level reporting, there’s nothing to schedule in real time: the Send document to AT step reports each document as it’s issued. In the SAF-T model, generate the month’s file on demand (from the supplier portal or the SAF-T endpoint) and upload it to the AT’s portal by the 5th of the following month; Invopop doesn’t generate or upload it automatically. Periodic VAT and IES are filed separately by the accountant.
Monthly SAF-T-PT XML uploaded to AT’s portal (no API for this), or real-time WebService XML calls per invoice. Both follow the same SAF-T schema; real-time submits one document at a time, SAF-T submits an aggregated file covering the month.
More answers in our Portugal FAQ section

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